Kuhnert Peter, Korczak Bożena M, Christensen Henrik, Bisgaard Magne
Institute of Veterinary Bacteriology, University of Bern, CH-3001 Bern, Switzerland.
Department of Veterinary Pathobiology, The Royal Veterinary and Agricultural University, DK-1870 Frederiksberg C, Denmark.
Int J Syst Evol Microbiol. 2007 Mar;57(Pt 3):625-632. doi: 10.1099/ijs.0.64659-0.
The taxonomic position of Actinobacillus capsulatus, a member of the family Pasteurellaceae found in rabbits, hares and hamsters, has been challenged. 16S rRNA gene (rrs) sequence data show the species to be heterogeneous. Using a polyphasic approach, 23 strains that were identified previously as belonging, or closely related, to A. capsulatus were analysed. Eighty characters were included in the phenotypic analysis. Phylogenetic analysis was done based on rrs, rpoB, infB and recN sequences. In addition, the recN sequence similarities were used to calculate the whole-genome sequence relatedness of all strains investigated as well as that with other members of the family Pasteurellaceae. The phenotypic analysis allowed identification of five groups. The major group of 17 strains could be classified as A. capsulatus. Two hamster isolates were closely related to A. capsulatus but differed in a few characters. Single isolates from a rabbit and snowshoe-hare were phenotypically related to Actinobacillus suis. One rabbit isolate was related to the genus Mannheimia, while another isolate could not be classified phenotypically with known taxa. The phylogenetic analysis confirmed the phenotypic grouping. In contrast to the rrs-based tree, the A. capsulatus strains clustered unambiguously with the type species and related species of the genus Actinobacillus in the rpoB-, infB- and recN-based trees. Genome similarity comparison using recN finally confirmed the high genomic relationship of the A. capsulatus strains with the type species and related species of the genus Actinobacillus and allowed a clear assignment of the other unrelated strains to the phenotypic and phylogenetic clusters outlined. The present findings allow the description of A. capsulatus to be emended and separate it more clearly from other species, both phenotypically and genotypically. The type strain of A. capsulatus is CCUG 12396(T) (=Frederiksen 243(T)=ATCC 51571(T)=NCTC 11408(T)=CIP 103283(T)).
在兔、野兔和仓鼠中发现的巴斯德氏菌科成员荚膜放线杆菌的分类地位受到了质疑。16S rRNA基因（rrs）序列数据显示该物种具有异质性。采用多相分类法，对先前鉴定为属于荚膜放线杆菌或与之密切相关的23株菌株进行了分析。表型分析纳入了80个特征。基于rrs、rpoB、infB和recN序列进行了系统发育分析。此外，recN序列相似性用于计算所有研究菌株以及与巴斯德氏菌科其他成员的全基因组序列相关性。表型分析确定了五个组。17株菌株的主要组可归类为荚膜放线杆菌。两株仓鼠分离株与荚膜放线杆菌密切相关，但在一些特征上有所不同。来自一只兔子和一只雪鞋兔的单个分离株在表型上与猪放线杆菌相关。一株兔子分离株与曼氏杆菌属相关，而另一株分离株在表型上无法与已知分类群进行归类。系统发育分析证实了表型分组。与基于rrs的树不同，在基于rpoB、infB和recN的树中，荚膜放线杆菌菌株与放线杆菌属的模式种和相关种明确聚类。使用recN进行的基因组相似性比较最终证实了荚膜放线杆菌菌株与放线杆菌属的模式种和相关种具有高度的基因组相关性，并允许将其他不相关菌株明确分配到所概述的表型和系统发育聚类中。目前的研究结果允许对荚膜放线杆菌的描述进行修订，并在表型和基因型上更清楚地将其与其他物种区分开来。荚膜放线杆菌的模式菌株是CCUG 12396(T)（=Frederiksen 243(T)=ATCC 51571(T)=NCTC 11408(T)=CIP 103283(T)）。
